Abstract
Using x-ray spectroscopy, we demonstrate the existence of 0.3-6 keV electrons in a low-pressure, low-power, magnetized plasma source, heated by an external radio-frequency antenna located at one end of an axisymmetric tandem mirror. X-ray measurements on low-bulk-temperature, Te,b ∼ 4 eV, hydrogen, neon, argon, and gas-mixture plasmas show spectra with high-energy tails having a near-Maxwellian form with Te,f up to 650 eV. The fast electrons producing these x-rays have densities in the range of 107-109 cm-3, 0.01%-1% of the bulk plasma density (up to 3 × 1011 cm-3), and so carry a significant fraction of the plasma energy and represent an important mechanism relevant to power coupling and heat flow in similar plasma sources.
Original language | English (US) |
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Article number | 030702 |
Journal | Physics of Plasmas |
Volume | 25 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1 2018 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics